The invention relates to a method for adjusting the axial play between the rotor and the stator of a motor. Methods for adjusting axial play are disclosed, for instance, by European Patent 00 65 585 and European Patent Application 01 33 527.
In the case of European Patent 00 65 585, a spacer sleeve which is provided with a thrust shoulder at one end facing the bearing can be pressed into a concentric recess of an insulating end disc resting against the end face of a laminated rotor stack with an axial immersion depth corresponding to the respective axial play, serves for the adjustment of the axial play.
In European Patent Application 01 33 527, a disc with a thickness corresponding to the calculated axial play is placed in a pocket fixed to the stator housing, for limiting the axial play of a shaft supported in slide bearings.
A method for adjusting an axial play with the following process steps is known from British Patent A-2 154 158:
(a) a first bearing is arranged with a press fit in a first closing cap;
(b) the first closing cap is mounted;
(c) one end face of a stator is arranged resting against the closing cap;
(d) a rotor with a shaft is inserted into the stator, one end of the shaft being introduced into the bearing;
(e) the distance between the opposite end face of the stator and a point on the shaft is measured;
(f) a second closing cap containing a second bearing is arranged over the other end of the shaft;
(g) the second closing cap is advanced relative to the other the other end of the shaft, so that the shaft can be taken up by the second bearing until the second closing cap rests against the opposite end face of the stator; and
(h) the first bearing is pressed into the first closing cap by a distance which is related to the measured distance, in order to fix the axial play of the shaft.
However, if a force fit between the bearing and the bearing abutment is absolutely necessary, it cannot be assured with certainty that the fixed adjustment position can be maintained, for instance, if the motor is used under rough operating conditions. With the subject of the present invention, a force fit can be dispensed with so that, with automatic adjustment of the bearing, the latter can be moved precisely with a small pressure and therefore also with small adjustment and can, on the other hand, be fixed in its adjusted position reliably also for use under rough operating conditions.